Is age or cardiovascular comorbidity the main predictor of reduced cerebrovascular pressure reactivity in older patients with traumatic brain injury?

Introduction: The Pressure Reactivity index (PRx) has been proposed as a surrogate measure for cerebrovascular autoregulation (CA) and it has been described that older age is associated with worse PRx. The etiology for this reduced capacity remains unknown. Research question: To investigate the relation between age and PRx in a cohort of patients with traumatic brain injury (TBI) while correcting for cardiovascular comorbidities. Material and methods: This is a retrospective analysis on prospectively collected data in 151 consecutive TBI patients between 2013 and 2023. PRx was averaged over 5 monitoring days and correlated with demographic, patient and injury data. A multiple regression analysis was performed with PRx as dependent variable and cardiovascular comorbidities, age, Glasgow motor score and pupillary reaction as independent variables. A similar model was constructed without age and compared. Results: Age, sex, thromboembolic history, arterial hypertension, Glasgow motor score and pupillary reaction significantly correlated with PRx in univariate analysis. In multivariate analysis, age had a significant worsening effect on PRx (p = 0.01), while the cardiovascular risk factors and injury severity had no impact. The comparison of the models with and without age yielded a significant difference (p = 0.01), underpinning the independent effect of age. Discussion and conclusion: In the present cohort study in TBI patients it was found that older age independently impaired cerebrovascular pressure reactivity regardless of cardiovascular comorbidity. Pathophysiology of TBI and physiology of ageing seem to line up to synergistically produce a negative effect on brain perfusion.

Profound prospective assessment of radiological and functional outcome 6 months after TBI in elderly.

BACKGROUND: Recovery after traumatic brain injury (TBI) in older adults is usually affected by the presence of comorbidities, leading to more severe sequelae in this age group than in younger patients. However, there are only few reports that prospectively perform in-depth assessment of outcome following TBI in elderly. OBJECTIVE: This study aims at documenting structural brain characteristics and functional outcome and quality of life in elderly patients 6 months after TBI and comparing these data with healthy volunteers undergoing the same assessments. METHODS: Thirteen TBI patients ≥ 65 years old, admitted to the University Hospitals Leuven (Belgium), between 2019 and 2022 due to TBI, including all injury severities, and a group of 13 healthy volunteers with similar demographic characteristics were prospectively included in the study. At admission, demographic, injury, and CT scan data were collected in our database. Six months after the accident, a brain MRI scan and standardized assessments of frailty, sleep quality, cognitive function, motor function, and quality of life were conducted. RESULTS: A total of 13 patients and 13 volunteers were included in the study, with a median age of 74 and 73 years, respectively. Nine out of the 13 patients presented with a mild TBI. The patient group had a significantly higher level of frailty than the control group, presenting a mean Reported Edmonton Frailty Scale score of 5.8 (SD 2.7) vs 0.7 (SD 1.1) (p < 0.01). No statistically significant differences were found between patient and control brain volumes, fluid attenuated inversion recovery white matter hyperintensity volumes, number of lesions and blackholes, and fractional anisotropy values. Patients demonstrated a significantly higher median reaction time in the One Touch Stockings of Cambridge (22.3 s vs 17.6, p = 0.03) and Reaction Time (0.5 s vs 0.4 s, p < 0.01) subtests in the Cambridge Neuropsychological Test Automated Battery. Furthermore, patients had a lower mean score on the first Box and Blocks test with the right hand (46.6 vs 61.7, p < 0.01) and a significantly higher mean score in the Timed-Up & Go test (13.1 s vs 6.2 s, p = 0.02) and Timed Up & Go with cognitive dual task (16.0 s vs 10.2 s, p < 0.01). Substantially lower QOLIBRI total score (60.4 vs 85.4, p < 0.01) and QOLIBRI-OS total score (53.8 vs 88.5, p < 0.01) were also observed in the patients' group. CONCLUSION: In this prospective study, TBI patients ≥ 65 years old when compared with elder controls showed slightly worse cognitive performance and poorer motor function, higher fall risk, but a substantially reduced QoL at 6 months FU, as well as significantly higher frailty, even when the TBI is classified as mild. No statistically significant differences were found in structural brain characteristics on MRI. Future studies with larger sample sizes are needed to refine the impact of TBI versus frailty on function and QoL in elderly.

Comparison of Intracranial Pressure and Pressure Reactivity Index Obtained Through Pressure Measurements in the Ventricle and in the Parenchyma During and Outside Cerebrospinal Fluid Drainage Episodes in a Manipulation-Free Patient Setting.

OBJECTIVE: We investigated the effect of cerebrospinal fluid (CSF) drainage on the intracranial pressure (ICP) signal measured in the parenchyma and the ventricle as well as the effect on the pressure reactivity index (PRx) calculated from both signals. METHODS: Ten patients were included in this prospective study. All patients received a parenchymal ICP sensor and an external ventricular drain (EVD) for CSF drainage. ICP signals (ICP-p and ICP-evd) were captured. Part of the study was a period of 90 min during which the patient was free from any manipulation, consisting of 30 min of drainage (O1), 30 min EVD closed (C) and 30 min of drainage (O2). RESULTS: Mean ICP-evd and mean AMP-evd increased (3.03 and 0.46 mmHg) from O1 to C and decreased (2.12 and 0.43 mmHg) from C to O2. ICP-p and AMP-p changes were less pronounced (closing EVD: +0.81 mmHg/+0.22 mmHg; opening EVD: -0.22 mmHg/-0.05 mmHg). Mean difference between PRx-evd and PRx-p was 0.12 for O1, 0.02 for C and -0.02 for O2. The intraclass correlation coefficient for absolute agreement of single measures was 0.66 for O1, 0.77 for C and 0.69 for O2. Mean PRx differences demonstrated a significant difference between O1 versus C and O1 versus O2 but not between C versus O2. CONCLUSION: Drainage of CSF reduces ICP magnitude and amplitude through the EVD. This effect was only marginal in parenchymal ICP measurements. In manipulation-free circumstances, agreement of PRx obtained through parenchymal and ventricular measurements was moderate to good, depending on the statistical method, and was not necessarily influenced by drainage.

Monitoring of Intracranial Pressure in Meningitis.

BACKGROUND: The literature on intracranial pressure (ICP) monitoring in meningitis is limited to case reports and a handful of descriptive series. The aim of this study is to investigate relationships among ICP, cerebral perfusion pressure (CPP), and outcome in meningitis and to identify whether ICP affected clinical decisions. METHODS: Between 1999 and 2011, a total of 17 patients with meningitis underwent ICP monitoring at the University Hospitals Leuven. Charts were reviewed for clinical history, ICP/CPP data, imaging findings, and Glasgow Outcome Scale score. Univariate correlations were computed for outcome and ICP/CPP variables, computed tomography characteristics, and Corticosteroid Randomization After Significant Head Injury outcome model variables. Treatment decisions were assessed regarding whether or not they were based on ICP. RESULTS: At drain placement, Glasgow Coma Scale scores showed a median of 8 (range 3-12). Six of 17 patients had either one or two nonreactive pupils. Significant correlations with outcome were found for the highest documented ICP value (r = -0.70), the number of episodes when CPP <50 mmHg (r =-0.50), the lowest documented CPP value (r = 0.61), and pupil reactivity (r = 0.57). Treatment was influenced by ICP in all patients. CONCLUSION: The results support the notion that in meningitis high ICP and low CPP represent secondary insults. The poor condition of the patients illustrates that the level of suspicion for increased ICP in meningitis may not be high enough.